MODIS Data Processing System MODAPS. Presented at the THIC Meeting at the Sheraton Barcelo in Annapolis MD on May 9, 2001

Transcription

1 MODIS Data Processing System MODAPS Curt Tilmes NASA Goddard Space Flight Center Code 922, Greenbelt MD Phone: Fax: Presented at the THIC Meeting at the Sheraton Barcelo in Annapolis MD on May 9, May 2001 THIC Meeting, Annapolis, MD - 1

2 MODIS Data Processing System MODAPS Curt Tilmes NASA Goddard Space Flight Center Code 922, Greenbelt MD Phone: Fax: Presented at the THIC Meeting at the Sheraton Barcelo Annapolis Hotel 173 Jennifer Road, Annapolis MD on May 9, 2001

3 MODIS MODerate resolution Imaging Spectroradiometer Key instrument on EOS-Terra and EOS-Aqua Missions 36 spectral bands from the visible through thermal infrared Spatial resolution: 250m(2 bands), 500m(5 bands), 1km (29 bands) Nearly complete global coverage in 1 day, all of Earth in 2 days More than 40 earth science products including: Sea Surface Temperature and Ocean Color, Cloud Properties and Aerosols, Land Surface Temperature, Vegetation Indices, Land Cover Change and Measures of Global Productivity 9 May 2001 THIC Meeting, Annapolis, MD - 3

4 Product Volumes Each MODIS instrument produces 70GB of raw data per day Goddard Earth Sciences Distributed Active Archive Center (GES DAAC) produces calibrated radiance, cloud mask and earth location products (295GB/day) and ships them to MODAPS MODAPS (MODIS Data Production System) makes the MODIS higher level science products (400GB/day) and ships them to the MODIS Science Team and to 3 DAACs for public distribution In 2003, the MODIS Team has a goal of producing up to 8TB of products per day and shipping 15TB per day to the community Current requirements are 3TB/day produced and 3TB shipped USGS EROS Data Center ships 55GB of Landsat 7 ETM+ scenes per day 9 May 2001 THIC Meeting, Annapolis, MD - 4

5 Data Product Flow DAACS EDC DAO DAO Data GES DAAC Archive & Distribute Land Data (ESDIS/ECS) White Sands EDOS L0 Processing (ESDIS/ EDOS) L0 Data Ingest & MODIS L1 Production (ESDIS/ECS) Ancillary Data L1 Products L1 Products MODAPS MODIS L2+ Production (SDST) L2+ Data GSFC Archive & Distribute L1+ and DAO (ESDIS/ECS) DATA PRODUCTS User Community Ancillary Data NOAA Sub-sampled L1B Product NASDA GLI Team MODIS Products MODIS Team Quality Assurance and Validation MODIS Products Update Product Quality NSIDC Archive & Distribute Snow & Ice (ESDIS/ECS) 9 May 2001 THIC Meeting, Annapolis, MD - 5

6 At Launch System 9 May 2001 THIC Meeting, Annapolis, MD - 6

7 Process Flow 9 May 2001 THIC Meeting, Annapolis, MD - 7

8 Level 2 9 May 2001 THIC Meeting, Annapolis, MD - 8

9 Level 2 Production 7 Level 2 PGEs Input 5 minute granules, output 5 minute granules 288 x 5 minute granules per day 144 day-mode, 144 night-mode executions Input ~730MB per 5 minutes Output ~580MB day-mode and 175MB night mode Around an hour of processing time for 5 minutes of data Very suited to distributed processing 9 May 2001 THIC Meeting, Annapolis, MD - 9

10 Land Gridded Production 9 May 2001 THIC Meeting, Annapolis, MD - 10

11 Distributed Architecture 9 May 2001 THIC Meeting, Annapolis, MD - 11

12 Distributed Architecture Much cheaper per processor cost for 2p nodes than central node Local disk space on processing nodes Copy input files down through Multiple Gigabit Ethernet to switched 100BaseT ~10MB/s, rcp in less than 2 minutes Read input files once on central node, then read repeatedly locally Process locally for a while, then copy outputs back to central node. 2GB RAM per node, caching benefit 9 May 2001 THIC Meeting, Annapolis, MD - 12

13 Online Disk At launch 10TB of LSI Logic Metastor (1 Filesystem!) Added Data Direct San Data Director Connected through 8 Host Fibre Channel Interfaces 20 Drive Fibre Channel Interfaces Dual 8+1 RAID, plus 2 spares channels Currently 35TB on primary host Soon another 28TB on reprocessing host ~70TB total online Split into 1TB per filesystem. Database tracks location of each file. 9 May 2001 THIC Meeting, Annapolis, MD - 13

14 Nearline Tape ADIC Scalar 1000 with 12 AIT-2 drives on both primary and reprocessing system tapes per jukebox. Connected via Chapparal Fibre Channel to SCSI bridges 50GB native, ~100GB with 2/1 compression 6MB/s native, we see 5-10MB/s About 2TB/day transfer to/from tape possible Retrieves take time mounting tapes, searching Not enough adding another 12 drives to each jukebox. Driven by homegrown database driven scripts calling Legato Networker Archive Option 9 May 2001 THIC Meeting, Annapolis, MD - 14

15 Summary With Aqua launching soon, and reprocessing needs growing, we need to continue scaling the whole system. Commodity Linux processors have good bang/$ All Level 2 and 2G processes ported to Linux/Intel HIPPI link to DAACs ~75MB/s = 6TB/day per system, Two systems (processing and reprocessing). DAACs have a big job scaling enough to meet long term archive and distribution needs 9 May 2001 THIC Meeting, Annapolis, MD - 15

16 MODIS Sample Images 9 May 2001 THIC Meeting, Annapolis, MD - 16

17 250M vs. 1KM 9 May 2001 THIC Meeting, Annapolis, MD - 17

18 16day 500M NDVI Composite 9 May 2001 THIC Meeting, Annapolis, MD - 18

19 Fire Detection 9 May 2001 THIC Meeting, Annapolis, MD - 19